Intermittent motion imprinter apparatus for packaging machines



July 18, 1967 w, YOUNG ET AL 3,331,320

INTERMITTENT MOTION IMPRINTER APPARATUS FOR PACKAGING MACHINES Filed Dec. 2, 1965 6 Sheets-Sheet l INVENTORS.

WILLIAM E. YOUNG ROBERT o. WOLFELSPERGER WILLIAM R. PA co ATTORNEY July 18, 1967 YQUNG ET AL 3,331,320

INTERMITTENT MOTION IMPRINTER APPARATUS FOR PACKAGING MACHINES INVENTORS. WILLIAM E. YOUNG 6 Sheets-Sheet 2 ROBERT O. WOLFELSPERGER WILLIAM R. W0

BY 10m Q Filed Dec. '2, 1965 A QRNE Y July 18, 1967 W. E. YOUNG ET AL INTERMITTENT MOTION IMPRINTER APPARATUS FOR PACKAGING MACHINES 6 Sheets-Sheet 5 Filed Dec. 2, 1965 m mm 0 S T wmm mvw E0. MT m Mm I A WILLIAM R. PASCO ATTORNEY July 18, 1967 w, YOUNG ET AL 3,331,320

INTERMITTENT MOTION IMPRINTER APPARATUS FOR PACKAGING MACHINES Filed Dec. 2, 1965 6 Sheets-Sheet F 7 INVENTORS.

' WILLIAM E. vouue Roam T 0. WOLFEL SPERGER WILLIAM R. PASCO "AIIQRNEY July 18, 1967 w. E. YOUNG ET AL 3,331,320

INTERMITTENT MOTION IMPRINTER APPARATUS FOR PACKAGING MACHINES Filed Dec. 2, 1965 I'M ,5 WI MIN/3;

6 Sheets-Sheet 5 ,lll

INVENTORS. WILLIAM E. YOUNG ROBERT 0. WOLFELSPERGER WILLIAM R. PAS 0 A o-MM (344M,

ATTORNEY July 18, 1967 w YOUNG ETAL 3,331,320

INTERMITTENT MOTION IMPRINTER APPARATUS FOR PACKAGING MACHINES Filed Dec. 2, 1965 6 Sheets-Sheet 6 I6! I62 537 [62g 7( !--/1[. ---I r LI .3 I

I F I65 I b 62 I! j |-'LJ T----- I m I76] I I7 I INVENTORS WILLIAM E. YOUNG ROBER T0. WOLFEL SPERGER WILLIAM R2260 BY mm,

A TTORNE Y United States Patent 3,331,320 INTERMITTENT MOTION IMPRINTER APPARA- TUS FOR PACKAGING MACHINES William E. Young, Stamford, Conn, and Robert 0. W0]- felsperger, Fairfield, and William R. Pasco, Newfoundlaud, N.J., assignors to Milprint, Inc., Milwaukee, Wis., a corporation of Delaware Filed Dec. 2, 1965, Ser. No. 511,111 2 Claims. (Cl. 101-292) This invention relates generally to the field of packaging machinery, and in its more specific aspects, it relates to an imprinter apparatus for attachment to a packaging machine that is adapted to imprint a legend onto a web of packaging film moving into the machine.

Our co-pending application Ser. No. 449,162 filed on Apr. 19, 196 5, relates to an imprinter apparatus for applying a legend to a web of film as it moves through a packaging machine that incorporates printing elements which move at a continuous rate of speed. In contrast, this application relates to an imprinter apparatus in which the printing elements are actuated to move intermittently.

A packager who desires to package a variety of products on the same packaging machine encounters problems when he must change from one product to the other. In the case of food products, for example, each product will require different information on the package relating to its name, ingredients, weight, price, etc. This can sometimes require the packager to carry an inventory of differently printed films for packaging his various products, or to use labeling equipment to apply labels to the package in order to apply individual information for different products. The apparatus of the present invention eliminates the need for resorting to labeling for the foregoing purposes and can eliminate or reduce the need to carry an inventory of different films for different products by providing an efiicient apparatus to print variable copy requirements on a web of packaging film as it is passing through a packaging machine. This enables a packager to adopt a web with a standardized pre-printed design applicable to a family of products, and then use the present apparatus to imprint the individual information on the pre-printed web in order to identify particular products.

This invention provides, among other features, an imprinter apparatus through which a web of packaging film is advanced and which includes a reciprocating printing plate assembly that is actuated to move into printing position to imprint a legend 0n the web and then return to an at-rest position when printing is completed. Roll-leaf is utilized by the imprinter as the ink supply and printing plate assembly is heated in order to effect transfer of ink from the roll-leaf onto the web to be printed. The imprinting apparatus incorporates a roll-leaf transport system that is adapted to move the ink a preselected distance after each printing operation in order to provide a fresh supply of roll-leaf in proper position for printing when the web is at rest. As another feature, the imprinter includes means for adjusting the position of the web to be printed vis-a-vis the printing plate assembly of the imprinter apparatus in order to obtain proper registration of the legend applied to the web by the imprinter, which feature is of particular importance when the web to be printed has a pre-printed design. Other particular structural details for effecting the desired cooperation and actuation of the basic mechanism of the imprinter apparatus will appear in the following description.

One of the main objects of this invention is to provide an imprinter apparatus which can be attached as an integral unit to a packaging machine and can apply a selected legend to film used by the packaging machine to enclose any selected article or commodity. Another is to provide an imprinter apparatus of the foregoing character which will include a reciprocable printing plate assembly which is adapted to print a Web of packaging film that can be moving through the apparatus at a continuous speed. Others are to actuate the foregoing printing assembly in response to the position of the portions of the web of packaging film which are to be imprinted, and to provide suitable control mechanisms which will facilitate such actuation. Still other main objects are to provide an imprinter apparatus which incorporates roll-leaf instead of a solvent type printing ink; to provide suitable apparatus for intermittently advancing the roll-leaf in order to insure a fresh supply for each printing operation; and to synchronize the actuation of the printing plate assembly and actuation of the roll-leaf transport mechanism so that the latter occurs upon completion of the former. One of the specific objects of this invention is to provide the new or improved details of construction hereinafter claimed.

The foregoing and other objects will become apparent from the following description which presents, for the purposes of illustration and not of limitation, one form of apparatus in which the present invention may be embodied. The description unfolds with reference to the drawings which form a part hereof and in which the same reference numeral refers to the same part in the several views:

FIG. 1 is a perspective view, with a portion removed, of a prior art packaging machine to which has been added the imprinter apparatus of the present invention;

FIG. 2 is a schematic representation showing the action of the present imprinter;

FIG. 3 is a typical package produced by the packaging machine illustrated in FIG. 1;

FIG. 4 is a side view of the imprinter apparatus of the present invention;

FIG. 5 is a top view of a portion of the apparatus in FIG. 4 illustrating the roll-leaf transport system;

FIG. 6 is a side view of a part of the apparatus of FIG. 4 illustrating elements of the roll-leaf transport system;

FIG. 7 is a sectional view of a portion of a shaft on which a supply roll of roll-leaf is carried, taken along the plane of line 77 in FIG. 6;

FIG. 8 is a sectional view taken along the plane of line 8-8 in FIG. 4 showing a portion of the apparatus;

FIG. 9 is a perspective view illustrating one of the elements shown in FIG. 8; and

FIG. 10 is a schematic diagram illustrating the electrical control circuit and pneumatic circuit for the imprinter apparatus of the invention.

PACKAGING MACHINE FIG. 1 illustrates one type of packaging machine on which the imprinter apparatus of this invention can be used, and the machine will be briefly described in order to show an application of the present invention in a typical environment. The machine 1 is designed to use two webs of material to package an article by forming cavities in one of the webs, which cavities are loaded with articles, then covering each filled cavity with a portion of the other web, sealing the two webs together and thereafter severing individual packages from the joined webs.

A first web 2, carried on a supply roll not shown, is drawn into the machine by a powered draw roll unit, also not shown, and clamped to a chain of trays 3 which moves in the direction of the arrows 4. The chain of trays is driven to move intermittently, and indexes first to a heating station 5 where the web is softened by heat, next to a forming station 6 where portions of the web are drawn by vacuum into the trays to form cup-like cavities 7 in the web, and then to a loading area 8 where product is delivered into each cavity 7 from a conveyor or by hand. The web is often referred to as the formed" web 9 because it is the web in which the product receiving cavities are formed by the machine.

A second web of packaging material is drawn into the machine 1 by powered draw roll units 11 and 12, passes over a dancer roll 13 pivotally mounted on arms 14 at each of its ends, and is then advanced under an idler roller 15 which applies the web 10 to the web 2 to cover the filled cavities in the web 2. The draw roll units 11 and 12 will usually be driven at different rotational speeds in order to stretch the web 10 to obtain accurate registration between it and the web 2. (The web It is often referred to as the fiat web since it is not formed into other shapes by the packaging machine as was the case with web 2.) The two webs then advance undera pivoted packaging head 16 which includes heat sealing means to partially seal the web 10 to the web 2 around the periphcries of the cavities formed in the latter web. The leading pair of partially sealed packages is then severed from the balance of the two webs by a knife (not shown) carried by the packaging head and moved to station 17 under the packaging head where each partially sealed pair of packages is evacuated and has the heat seals completed; if desired, the packages can be filled with an inert gas at this station. The sealed pair of packages is still clamped to the chain of trays 3 which passes over change-of-direction rollers (not shown) to move in the direction of the arrow 18 and the inverted pair of packages is then removed from the chain and transferred to a power conveyor belt 19 along which they are moved to engage a cutting die 20 and be cut into individual packages; thereafter, they are discharged from the conveyor.

Several types of machines as described above are commercially available and US. Patent 3,061,984 contains a complete description of the illustrated machine. It is pointed out, however, that the imprinter apparatus of this invention can be used with other types of machines, and the specific type shown is for the purposes of illustrating the succeeding description; the machine itself forms no part of the present invention. The webs 2 and 10 can be thermoplastic film so that they can be formed and sealed by heat as required in the several machine operations.

A typical package formed by the packing machine described above is shown in FIG. 3. The lower portion of the package consists of a part of a web 2 which has been vacuum-formed by the machine so as to include a product-receiving cavity 7 surrounded by peripheral flange 26. The upper portion of the package consists of a flat portion of the web It and the two portions are sealed together along the flange areas to enclose the product 27 which is inserted in the cavity 7.

IMPRINTER DESCRIPTION The imprinter of this invention is designed to be attached to a packaging machine such as shown in FIG. 1 and apply a printed legend to one of the webs of film as it is being drawn into the packaging machine. In FIG. 1, the imprinter 3t) is shown as being attached to the machine so as to apply an imprinted legend to the flat web 10, and is clamped on to a shaft 31 of the packaging machine, which shaft 31 would carry a supply roll of the web 16 if the imprinter apparatus were not attached to the machine; the imprinter itself has a shaft 32 which carries a supply roll of web it when the imprinter is attached to the packaging machine.

A typical use of the imprinter is illustrated schematically in FIG. 2 wherein web 10 carrying a pre-printed background design 33 is led through the imprinter printing station 34 where an auxiliary legend 35 is applied to the web 10 in a selected relation to the pre-printed design 33. In a typical use of the imprinter, the pre-printed design 33 will be background design common to several types of commodities and the auxiliary legend 35 will consist of variable information pertaining to specific products, such as product name, ingredients, cost, etc. Through the use of the imprinter, a packager can adopt a pre-printed web 10 that can be used with many types of commodities and then merely alter the imprinted auxiliary legend as required for individual commodities. The relationship between the two designs in a finished package is shown in FIG. 3.

(1) Supporting frame of the imprinter The imprinter 30 includes a frame structure which supports the various operative elements of the imprinter so that the imprinter itself forms an integral machine that can be readily attached to a selected packaging machine. Referring now to FIGS. 1 and 4, the imprinter frame comprises a main beam 40, a rear wall 41 joined to the main beam, and a front wall 42 joined to the rear wall along end wall 43 and end wall 44. The main beam is joined to shaft 31 of the packaging machine by means of a clamp ring 45 near its forward end.

A control box 46 (see FIG. 1) is supported on a pedestal 47 connected to the main beam 40 and houses the various control elements used to regulate the operative mechanisms of the imprinter hereinafter described.

(2) Transport of packaging web through imprinter Turning now to FIG. 4, a supply roll of the web 10 is journalled at one of its ends in the main beam 40 of the imprinter. As the web 10 is led off its supply roll it passes under an edge guide 50 pivoted to the main beam which maintains proper transverse positioning of the web relative to the imprinter and the packaging machine. The edge guide straddles the web 10 and has elements which contact each edge of the web to obtain the desired effect. The web passes over an idler roller 51 cantilevered from the rear wall 41 of the imprinter. Next, the web passes around idler rollers 52, 53, and 54 which are journalled between the front and rear walls of the imprinter; after which the web 10 passes upwardly over roller 55 and then under roller 56 after which it is led through the powered draw roll unit 11 of the packaging machine.

The roller 55 is pivotally mounted on the imprinter frame so that its position relative in the frame of the imprinter can be altered. The specific mechanism for this purpose in the illustrated embodiment includes a shaft 57 (best shown in FIG. 1) extending between the front and rear walls of the imprinter and which has a first worm 58 attached to its central portion and which meshes with a worm wheel 59 carried on a shaft 60 supported in blocks 61 and 62. A second worm 63 is carried on the shaft 60 and meshes with a second worm wheel 64 carried on a shaft 65 supported on the imprinter frame. At each end of the shaft 65, an arm 66 is mounted and the roller 55 has its ends attached to the outer portion of each arm 66. The shaft 57 extends through the front wall 42 of the imprinted and has a knob (see FIG. 1) secured to its projecting end. Manual rotation of the knob 67 moves the worm gearing just described and will cause pivotal rotation of the roller 55 relative to the shaft 65 and thereby manually decrease or increase the length of the path of travel of the web 10 through the imprinter after the printing station to thereby allow adjustment of the time of printing relative to the packaging machine 1; as the roller 55 is raised relative to the imprinter frame, the path of travel of the web is increased.

The imprinter 30 of this invention does not include any drive mechanism for drawing the web 10 of packaging film through the imprinter. Instead, the web 10 is drawn off the supply roll carried on the shaft 32 of the imprinter by means of the powered draw roll unit 11 of the packaging machine. Hence, the imprinter has no independent web drive mechanism that would have to be synchronized with the web transport mechanism of the packaging machine, thereby simplifying the imprinter mechanism and facilitating obtaining proper registration of the imprinted legend applied to the packaging film by the imprinter with any pre-printed design carried on the film.

(3) Ink supply system for the imprinter The imprinter of this invention utilizes roll leaf which comprises pigment carried on a carrier film of suitable material (such as glassine paper, cellulose acetate or Mylar) and wherein the pigment can be transferred to the web to be printed upon the application of heat and the roll leaf contacting a web, the web to be imprinted softens slightly and is impregnated with the size coating of the roll leaf so that the coating of the roll leaf separates from the carrier film and becomes joined to the imprinted web. The term roll leaf as used hereinafter refers to this general type of material, which is also known as hot transfer roll leaf. Materials of this type are wellknown and commercially available from several suppliers.

' Referring again to FIG. 4, a supply roll of a web 75 of roll leaf is wound on a supply reel 76 that is carried on a fixed shaft 77 cantilevered from the rear wall 41 of the imprinter. The web 75 of roll leaf is led from the reel 76 over idler shaft 78 journalled from the rear wall of the imprinter, between the idler roller 53 and idler roller 79, both journalled between the front and rear Walls of the imprinter, thence across the imprinter through the nip formed between a rubber-covered roller 80' and a metal roller 81, after which it is led onto a rewind shaft 82 mounted cantilevered from rear wall 41 of the imprinter.

As shown in FIG. 1, two webs 75 of roll leaf are mounted side-by-side on the shaft 77 so that the imprinter can apply two legends simultaneously to the web which will often have two rows of pre-printed designs 33 as shown in FIG. 2. Naturally, there can be only one web of roll leaf, or more than two webs, used by the imprinter, depending on the requirements of the web to be printed.

In order to draw the roll leaf web or webs through the imprinter to present a fresh supply of roll leaf after each printing, the rubber-covered roller 80' is driven by the mechanism which will now be described. Starting at FIG. 4, a double-acting-air cylinder 85 is attached to the rear wall 41 of the imprinter and has a reciprocable shaft 86 that is connected at its upper end through a block 87 to a chain 88. The chain 88 is first trained about a sprocket 89 keyed to a cross-shaft 90 (see FIG. 5) journalled between the rear wall 41 and'front wall 42 of the imprinter and then trained about an idler sprocket 91 mounted on the rear wall. The end of the chain 88 is attached to a spring 92 which is secured to the imprinter frame at its opposite end and acts to keep the chain taut. Turning now to FIG. 5, the cross-shaft 90, at its end opposite from the sprocket 89, carries a gear 93 which is attached to the cross-shaft through a oneway clutch 94 so that the gear 93 will turn in only one direction. The gear 93 meshes with a gear 95 which is attached through a one-way clutch 96 carried on the shaft 97 of the rubber-covered roller 80.

The rewind shaft 82 is driven from a sprocket 98 (see FIG. 5) keyed to the shaft 97 of the rubber-covered roller 80, and a chain 99 (see FIG. 4) that is trained about the sprocket 98 and a sprocket 100 attached to the rewind shaft 82. An idler sprocket 101, mounted on the rear wall 41, engages the chain 99 to keep it taut.

The metal roller 81 is carried in a pair of opposed arms 102 (best shown in FIG; 5) which are pinned at 103 (FIGS. 4 and 6) to the imprinter walls to pivotally mount the roller 81 with respect to the roller Turning to FIG. 6', a spring 104 is connected between each arm 102 and an imprinter wall to urge the metal roller 81 into engagement with the rubber-covered roller 80. An eccentric cam 105 is mounted on an imprinter wall and bears against an arm 102 to move the metal roller 81 into and out of contact with the rubber-covered roller 80. When the metal roller 81 contacts the rubbercovered roller 80, a web 75 of roll leaf is gripped between them so as to be advanced upon rotation of the roller 80.

The operation of the above-described mechanism for drawing a web of roll leaf 75 off its supply reel is as follows. When air under pressure is admitted into the upper portion of the double-acting air through air hose 108, the shaft 86 is moved downwardly to move the chain 88 so as to rotate the sprocket 89 and cross-shaft 90, which rotation is transmitted to the rubber-covered roller 80 through the gears 93- and to rotate the roller 80 clockwise as shown by the arrow 107 in FIG. 4.

With the web 75 held against the roller 80 by the metal roller 81, the web is advanced a selected distance. At the same time, the rewind shaft 82 is rotated by the chain 99 to take up the length of web that was advanced. An adjustable nut 106 on the lower end of the shaft 86 of the air cylinder 85 acts to control the stroke of the shaft 86 and hence control the length of web 75 advanced on each downward stroke of the shaft 86. After completion of the downward movement of the shaft 86, air under pressure is admitted into the lower portion of the cylinder 85 through air hose 109 to drive the shaft 86 upwardly; the chain 88 also moves upwardly, but because of the one-way clutches 94 and 96, the rubber-covered roller 80 and rewind shaft 82 do not rotate upon upward movement of the shaft 86.

FIG. 7 shows a detailed view of the internal construction of the shaft 77 which carries the supply roll of each web 75 of roll leaf. The shaft 77 has a groove 110 in which a moveable member 111 is inserted and is held against the heads of bolts 112 by means of springs 113. A sleeve 114 fits over the moveable member 111 and the reel 76 is fitted over the sleeve 114. This construction enables the reel 76 to rotate to draw of web 75 even though the shaft 77 is stationary. The rewind shaft 82 has a similar construction and the end of each web 75 is attached to a sleeve 114 on the rewind shaft.

(4) Printing plate assembly of the imprinter Turning now to FIG. 8, a plate is attached between the rear wall 41 and front wall 42 of the imprinter. A rubber back-up pad 121 is attached to the underside of the plate 120.

A printing plate assembly 122, shown in FIG. 9, is inserted underneath the back-up pad 121 and comprises a drawer-like unit including a shelf 123, a front panel 124, and a pair of plate holders mounted tn the shelf 123.

Returning to FIG. 8', the printing plate assembly 122 is inserted between the front and rear walls with the shelf 123 extending through the rear wall.

The right hand plate holder 125 is sectioned in 'FIG. 8 to expose its internal construction, the other plate holder being of the same construction. A sleeve 127 extends through the shelf 123 and is secured to the shelf by a clamp ring 131. A block 128 is attached to the upper end of the sleeve 127. A plunger 129 is inserted inside the sleeve 127 and is supported in suitable bearings for reciprocating motion relative to the sleeve. The upper end of the plunger 129 is secured to the plate holder 125 and a flanged cap 130 is attached to the lower end of the plunger. A spring 132 extends'betwen the flanged cap 130 and the clamp ring 131.

On the upper surface of each plate holder 125, a printing plate 133 fits about guide pins 134 and is held in place by magnets 135. The printing plates carry the legend to be 7 applied by the imprinter. The two plate holders 125 are tied together by an anti-rotation bar 136, see FIG. 9, to reduce twisting movement of the plate holders. The web 10 and the two webs 75 of roll leaf pass through the space between the rubber back-up pad 121 and the printmg plates 133 as shown in the drawings. Each plate holder 125 and its supporting structure is mounted on the shelf 123 in such manner as to enable lateral adjustment of the plate holders in order to align the printing plates 133 in registration with the positions on the web 10 which is to be imprinted by the imprinter.

Inserted in each plate holder 125 is an electric heating element 140, which elements are powered by wires 141 and 142 connected to a plug 143 that engages a socket 144 conected to a power line 145 when the assembly 122 is fully inserted in position in the imprinter frame. A suitable sensor not shown is carried in each plate holder 125 to control its temperature.

Imprinting of the web 10 is accomplished when the plate holders 125 are heated by the heaters 140 and moved upwardly to grip the web 10 and a web 75 between the rubber back-up pad 121 and printing plate 133 for a sufficient dwell time and with sufficient pressure to transfer roll leaf onto the web 10 to form the imprinted legend.

The plate holders 125 are moved upwardly for the above printing operation by means of double-acting air cylinders 146, the right-hand air cylinder 146 being sectioned to reveal its internal structure. Each cylinder 146 has a reciprocable shaft 147 which projects through each end of cylinder body and slides through bearings 148. A piston 149 is joined to an intermediate portion of the shaft 147 within a chamber 150 inside the valve body. A down-port 151 communicates with the portion of the chamber 150 above the piston 149 and an up-port 152 communicates with the portion of the chamber 150 underneath the piston 149. When air under pressure is admitted through air hose 153 into the up-port 152, the shaft 147 is driven upwardly so that its uppermost end contacts the flanged cap 130 attached to plunger 129 and moves a plate holder 125 upwards with sufficient pressure for imprinting a legend on the web 10. After imprinting is completed, air under pressure is admitted through air hose 154 into the down-port 151 to move the shaft 147 downwardly out of contact with the flanged cap 130; following this, the spring 132 moves the plate holder 125 downward to bring the printing plate 133 out of engagement with the webs 10 and 75. A stop nut 155 is threaded on the bottom of shaft 147 to adjust its stroke during the foregoing movemen-t. Each air cylinder 146 is rigidly attached to a base plate 156 by clamp rings 157, and the base plate is joined to the rear wall 41 and front wall 42 of the imprinter.

() Control circuits FIG. diagrams the electrical control and pneumatic circuits used to direct and actuate the printing and roll leaf advancing operations, the electrical wires being shown in dashed lines and the air hoses in solid lines.

A photoelectric scanner 161 is connected by wire 162 to an amplifier 163 which is wired to timer switches 164 and 165 through wires 162a and 16212. Solenoid valve 166 controls the admission of high pressure air into either air line 153 and 154 from supply line 167 which includes a regulator 168 to maintain the air at a design pressure. Solenoid valve 169 controls admission of high pressure air into either air line 108 or 109 and is also connected to the air supply through line 170 which has a regulator 171 to maintain the design pressure. Wire 172 is connected from a terminal of timer switch 164 to solenoid valve 166 to move the valve to allow air to flow into air hose 153 and exhaust air hose 154 when energized, and wire 173 runs from terminal A of the timer switch 164 to the solenoid 166 to move it to the position in which are is admitted into air hose 154 and air is exhausted from air hose 153 when it is energized. Wire 174 runs from wire 173 to solenoid valve 169 to move the valve to admit air into air hose 108 and exhaust air hose 109 when energized, and wire 175 runs from terminal A of the timer switch 165 to solenoid valve 169 to move it to admit into air hose 109 and exhaust air hose 108 when energized. Wire 176 runs from wire 175 to the amplifier 163 for the purpose stated below.

Looking now at FIGS. 1 and 4, the photoelectric scanner 161 is mounted on a bracket 180 clamped to the rear wall 41 of the imprinter so as to be adjustable. When a pre-printed web 10 is to be imprinted by the imprinter 30, the web will have spaced eyespots printed in a margin of the web. When an eyespot passes under the photoelectric scanner 161 to interrupt its light beam, the following sequence occurs:

(1) Current is sent through wires 162, 162a and 162b to energize timer switches 164 and 165, which allows current to be sent through wire 172 to energize solenoid valve 166 to admit air into air hose 153 and thereby cause the reciprocable shaft 147 of each air cylinder 146 to move upwards and print the web 10.

(2) After a pre-set time interval timer switch 164 times out and switches to its terminal A to send current through wire 173 to cause solenoid valve 166 to shift to supply air into air hose 154 (and exhaust hose 153) and thereby move the reciprocable shafts 147 downward to halt the printing operation. Simultaneously, current is sent through wire 174 to energize solenoid valve 169 to admit air into air hose 108 to move the reciprocable shaft 86 of air clyinder downwards and thereby advance each web 75 of roll leaf a selected distance equal to the width of the imprinted legend plus a small allowance for spacing; this brings fresh roll leaf into position for the next printing operation and advance of each web of roll leaf is halted when this is accomplished.

(3) After a second pre-set time interval, timer switch times out and switches to its terminal A to send current through wire and energize solenoid valve 169 to move and admit air into air hose 109 (and exhaust air hose 108) which causes the shaft 86 of air cylinder 85 to move upwards; for the reason previously described, there is no advance of the roll leaf during this movement of the shaft 86, but the air cylinder 85 is merely re-set. Simultaneously, current is sent through wire 176 to re-set the scanner 161 for the next cycle.

The preceding cycle is repeated when the next eyespot of the continuously moving web 10 passes under the scanner 161. In an actual installation of an imprinter of this invention, the above cycle took 0.15 second, during which the printing plates contacted the web in the printing position for only a part of the time. Air at 80 psi. was satisfactory to actuate the cylinders 85 and 146.

If an unprinted web 10 is to be imprinted, the photoelectric scanner is eliminated and replaced by a cycle switch to control the electric circuit for actuation of the air cylinders 146 and 85.

There has thus been described an imprinter apparatus capable of satisfying the objects of the present invention. The imprinter 30 can be utilized to imprint a selected legend on a web of film moving through the imprinter at a continuous rate of speed, particularly when the web is not moving too fast and is of a material that can be stretched slightly during the short period of time that it is gripped between the printing plates and the back-up pad for the imprinting operation. Plastic films commonly used in packaging have this ability and can be accommodated, such as uncoated and saran-coated Mylar polyester film; coated or uncoated nylon films; cellophane, cellophane laminated to foil and polyethylene; saran-coated cellophane; heat stabilized, biaxially-oriented polypropylene; and polyethylene. Speeds of 30 packages per minute with a five and one-quarter inch imprinted legend repeat have been satisfactorily handled with a continuous moving web on the imprinter. If the packaging machine is operating too fast or if the film is not elastic, a dancer roll can be placed between the printing position and the powered draw roll units of the packaging machine to allow the film to be fed to the drawing roll while the printing plates grip and momentarily stop the film; also, an electrical or mechanical system could be utilized to stop the powered draw roll units of the packaging machine which draws the web to be printed through the imprinter for a short period of time while the imprinter is imprinting the legend. Thus, by either of the latter two systems, the imprinter of this invention can be adapted to print on film which is temporarily halted during the printing sequence.

As has been demonstrated in the preceding description, the imprinter apparatus of the present invention includes a reciprocable printing plate assembly and an intermittently advancing roll leaf feed system. Actuation of the two systems is controlled with respect to one another and can be operated to print either pre-pn'nted or unprinted film. While the imprinter has been illustrated herein as being used to print plastic films such as commonly used in packaging, it is pointed out that it may also be utilized to print other films such as paper, board, cloth, etc. Also, while the imprinter was specifically developed for attachment to packaging machinery, it is possible that it may find use on other types of machines which utilize webs of material or as an independent unit.

It is to be understood that it is intended to cover all changes and modifications of the embodiment of this invention herein chosen for the purpose of illustration, as Well as other embodiments, which do not depart from the spirit and scope of this invention.

We claim:

1. An imprinter apparatus for use on a packaging machine of the type adapted to receive a web of packaging film and enclose product therewith to form individual packages, which packaging machine includes means for drawing the web of packaging film into the machine, said imprinter comprising:

(1) a frame adapted for attachment to the packaging machine, a shaft mounted in the frame for carrying a supply roll of the Web of packaging film, and a plurality of roller means attached to the frame and around which the web of packaging film travels on its way to the aforesaid means for drawing it into the packaging machine, said roller means establishing a path of travel of predetermined length of the web of packaging film through the imprinter between the first and last of said roller means;

(2) a printing station comprising a stationary back-up member and a reciprocable printing plate assembly spaced from each other, the aforesaid roller means including rollers arranged to guide the web of packaging film through the space between the back-up member and reciprocable printing plate assembly, and the printing plate assembly including at least one heated printing plate element;

(3) means for supplying at least one web of roll leaf into the space between the back-up member and reciprocable printing plate assembly, said means 10 comprising a supply shaft for holding a supply of roll leaf on one side of the printing station and a rewind shaft for receiving used roll leaf on an opposite side of the printing station, said roll leaf including a coating and a carrier film wherein the coating is separable from the carrier film upon the application of heat and pressure;

(4) means for reciprocating the printing plate assembly between (a) a first position in which the web of packaging film and a web of roll leaf is gripped between printing plate elements of said assembly and the back-up member to transfer coating from the roll leaf to the packaging film upon the application of heat and pressure and thereby imprint the packaging film with a selected legend; and (b) a second position in which the printing plate assembly is spaced from the back-up member;

(5) means for intermittently advancing the web of roll leaf after a legend has been imprinted to supply fresh roll leaf coating for imprinting a next legend, said means being adapted to advance the roll leaf a distance equal to at least the length of roll leaf required for each legend and then halt such advancement until a next legend is imprinted, and said means comprising (a) a double-acting air cylinder connectable to a source of air under pressure and having a reciprocable shaft, (b) a draw roller over which the roll leaf passes, (c) a second roller urged against the draw roller to hold roll leaf thereon, and (d) means driving the draw roller from the reciprocable shaft of the air cylinder upon movement of said shaft in one direction; and

(6) at least one of the aforesaid roller means over which the Web of material travels through the imprinter being positioned subsequent to the printing station and being adjustable to alter the length of the path of travel of the web after it has been imprinted.

2. Apparatus according to claim 1 further including means connecting the draw roller and the rewind shaft for driving the rewind shaft upon rotation of the draw roller.

References Cited UNITED STATES PATENTS 1,955,798 4/1934 Fassmann 101-288 2,053,473 9/ 1936 Gould et al.

2,497,909 2/1950 Poole 10l181 2,500,230 3/1950 Bailey et a1. 101-181 2,521,435 9/1950 Wockenfuss 101-288 X 2,621,435 12/1952 Weber.

2,706,354 4/1955 Weber.

2,714,268 8/1955 Battey.

3,217,638 11/1965 Gottscho 101-27 ROBERT E. PULFREY, Primary Examiner.

W. F. MCCARTHY, Assistant Examiner. 

1. AN IMPRINTER APPARATUS FOR USE ON A PACKAGING MACHINE OF THE TYPE ADAPTED TO RECEIVE A WEB OF PACKAGING FILM AND ENCLOSE PRODUCT THEREWITH TO FORM INDIVIDUAL PACKAGES, WHICH PACKAGING MACHINE INCLUDES MEANS FOR DRAWING THE WEB OF PACKAGING FILM INTO THE MACHINE, SAID IMPRINTER COMPRISING: (1) A FRAME ADAPTED FOR ATTACHMENT TO THE PACKAGING MACHINE, A SHAFT MOUNTED IN THE FRAME FOR CARRYING A SUPPLY ROLL OF THE WEB OF PACKAGING FILM, AND A PLURALITY OF ROLLER MEANS ATTACHED TO THE FRAME AND AROUND WHICH THE WEB OF PACKAGING FILM TRAVELS ON ITS WAY TO THE AFORESAID MEANS FOR DRAWING IT INTO THE PACKAGING MACHINE, SAID ROLLER MEANS ESTABLISHING A PATH OF TRAVEL OF PREDETERMINED LENGTH OF THE WEB OF PACKAGING FILM THROUGH THE IMPRINTER BETWEEN THE FIRST AND LAST OF SAID ROLLER MEANS; (2) A PRINTING STATION COMPRISING A STATIONARY BACK-UP MEMBER AND A RECIPROCABLE PRINTING PLATE ASSEMBLY SPACED FROM EACH OTHER, THE AFORESAID ROLLER MEANS INCLUDING ROLLERS ARRANGED TO GUIDE THE WEB OF PACKAGING FILM THROUGH THE SPACE BETWEEN THE BACK-UP MEMBER AND RECIPROCABLE PRINTING PLATE ASSEMBLY, AND THE PRINTING PLATE ASSEMBLY INCLUDING AT LEAST ONE HEATED PRINTING PLATE ELEMENT; (3) MEANS FOR SUPPLYING AT LEAST ONE WEB OF ROLL LEAF INTO THE SPACE BETWEEN THE BACK-UP MEMBER AND RECIPROCABLE PRINTING PLATE ASSEMBLY, SAID MEANS COMPRISING A SUPPLY SHAFT FOR HOLDING A SUPPLY OF ROLL LEAF ON ONE SIDE OF THE PRINTING STATION AND A REWIND SHAFT FOR RECEIVING USED ROLL LEAF ON AN OPPOSITE SIDE OF THE PRINTING STATION, SAID ROLL LEAF INCLUDING A COATING AND A CARRIER FILM WHEREIN THE COATING IS SEPARABLE FROM THE CARRIER FILM UPON THE APPLICATION OF HEAT AND PRESSURE; (4) MEANS FOR RECIPROCATING THE PRINTING PLATE ASSEMBLY BETWEEN (A) A FIRST PORTION IN WHICH THE WEB OF PACKAGING FILM AND A WEB OF ROLL LEAF IS GRIPPED BETWEEN PRINTING PLATE ELEMENTS OF SAID ASSEMBLY AND THE BACK-UP MEMBER TO TRANSFER COATING FROM THE ROLL LEAF TO THE PACKAGING FILM UPON THE APPLICATION OF HEAT AND PRESSURE AND THEREBY IMPRINT THE PACKAGING FILM WITH A SELECTED LEGEND; AND (B) A SECOND POSITION IN WHICH THE PRINTING PLATE ASSEMBLY IS SPACED FROM THE BACK-UP MEMBER; (5) MEANS FOR INTERMITTENTLY ADVANCING THE WEB OF ROLL LEAF AFTER A LEGEND HAS BEEN IMPRINTED TO SUPPLY FRESH ROLL LEAF COATING FOR IMPRINTING A NEXT LEGEND, SAID MEANS BEING ADAPTED TO ADVANCE THE ROLL LEAF A DISTANCE EQUAL TO AT LEAST THE LENGTH OF ROLL LEAF REQUIRED FOR EACH LEGEND AND THEN HALT SUCH ADVANCEMENT UNTIL A NEXT LEGEND IS IMPRINTED, AND SAID MEANS COMPRISING (A) A DOUBLE-ACTING AIR CYLINDER CONNECTABLE TO A SOURCE OF AIR UNDER PRESSURE AND HAVING A RECIPROCABLE SHAFT, (B) A DRAW ROLLER OVER WHICH THE ROLL LEAF PASSES, (C) A SECOND ROLLER URGED AGAINST THE DRAW ROLLER TO HOLD ROLL LEAF THEREON, AND (D) MEANS DRIVING THE DRAW ROLLER FROM THE RECIPROCABLE SHAFT OF THE AIR CYLINDER UPON MOVEMENT OF SAID SHAFT IN ONE DIRECTION; AND (6) AT LEAST ONE OF THE AFORESAID ROLLER MEANS OVER WHICH THE WEB OF MATERIAL TRAVELS THROUGH THE IMPRINTER BEING POSITIONED SUBSEQUENT TO THE PRINTING STATION AND BEING ADJUSTABLE TO ALTER THE LENGTH OF THE PATH OF TRAVEL OF THE WEB AFTER IT HAS BEEN IMPRINTED. 